Problem: $ { \left[\begin{array}{rr}{1} & {2} \\ {1} & {0}\end{array}\right]-\left[\begin{array}{rr}{4} & {-2} \\ {2} & {4}\end{array}\right] = {?} } $
Explanation: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{1}-{4} & {2}-{-2} \\ {1}-{2} & {0}-{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-3} & {4} \\ {-1} & {-4}\end{array}\right]}$